1. Field of the Invention
The present invention relates to a scroll compressor, and in particular to a scroll compressor having a reversion preventive device which is capable of preventing a compressor from being operated in a reverse direction of a direction for compressing a fluid.
2. Description of the Prior Art
In general, there are various types of compressors according to compression methods, among them a scroll compressor is mainly used for an air conditioner required to have a small size and light weight.
FIG. 1 is a sectional view illustrating the conventional scroll compressor.
The conventional scroll compressor includes a casing 106 in which a suction pipe 102 for sucking a fluid is connected, a discharge pipe 104 for discharging a compressed fluid is connected and having a certain sealed space; a driving unit 108 arranged at the lower portion of the casing 106 and generating a driving force; and a compressing unit 110 arranged at the upper portion of the casing 106, connected to the driving unit 108 through a rotational shaft 112, compressing the fluid sucked into the suction pipe 102 and discharging the fluid through the discharge pipe 104 according to the rotation of the rotational shaft 112.
A main frame 114 is installed at the upper portion of the casing 106 in order to support the upper portion of the rotational shaft 112 rotatively and support the compressing unit 110, and a lower frame 116 is installed at the lower portion of the casing 106 in order to support the lower portion of the rotational shaft 112 rotatively.
The driving unit 108 includes a stator 122 fixed in the circumferential direction of the casing 106; and a rotor 124 arranged at the inner circumference of the stator 122 and fixed to the rotational shaft 112. When power is applied to the stator 122, the rotor 124 is rotated by the mutual operation of the stator 122 and the rotor 124, and accordingly the rotational shaft 112 is rotated.
The compressing unit 110 includes a fixed scroll 128 having an involute-shaped fixed wrap 126 and fixed to the upper portion of the casing 106; and an orbiting scroll 132 having an involute-shaped orbiting wrap 130 corresponded to the fixed wrap 126 so as to have a certain compression space 118 therebetween, supported by the main frame 114 and performing an orbiting operation in the rotation of the rotational shaft 112.
A discharge hole 136 is formed at the center of the fixed scroll 128 in order to discharge the fluid compressed by the mutual operation of the fixed wrap 126 and the orbiting wrap 130, and a check valve 138 is installed at the upper portion of the discharge hole 136 in order to prevent the discharge fluid from being flowed backward.
An oldhams ring 150 is installed between the orbiting scroll 132 and the main frame 114 in order to prevent the orbiting scroll 132 from being rotated, and a separating panel 120 is installed at the top surface of the fixed scroll 128 in order to divide the inner space of the casing 106 into a lower pressure side and a high pressure side.
In the above-described conventional scroll compressor, when power is applied to the stator 122, the rotor 124 is rotated by the mutual operation of the stator 122 and the rotor 124, and the rotational shaft 112 fixed to the rotor 124 is rotated in the forward direction. Then, according to the rotation of the rotational shaft 112, the orbiting scroll 132 performs the orbiting operation, compresses the fluid sucked through the suction pipe 102 and discharges it through the discharge pipe 104 by the mutual operation with the fixed scroll 128.
Herein, it is possible to prevent the fluid discharged to the high pressure side through the discharge hole 136 from being flowed backward in the low pressure side by the check valve 138 installed at the discharge hole 136.
However, in the conventional scroll compressor, when a single-phase motor is used as a driving unit for generating a rotational force, if a load occurred in the operation is greater than a motor torque, a rotational force of the motor may be reduced, even worse the motor may be rotated in the backward direction, in that case vibration and noise may occur due to the wrong operation, and accordingly reliability of the compressor may be lowered.
In addition, when a three-phase motor is used as a driving unit for generating a rotational force, if the wrong connection of the motor occurs, the motor may be rotated in the backward direction, in that case vibration and noise may occur due to the wrong operation, and accordingly reliability of the compressor may be lowered.